Great aesthetic! And I loved the extra work you did to make the game feel like a late 90s windows app. Even though this kind of sliding block puzzle isn't my favorite type of game, I had a blast clicking through the menus and taking in the atmosphere. The stock sound effects were a hoot, too!
It did seem like there were a few stages where the boxes could wrap the screen in one horizontal line, but not another - it might help to add a visual indicator if this is intended.